Such vibrating conveyers are used to convey material by means of nonuniform reciprocating motion, the conveyer trough being, in principle, horizontal or near horizontal, whereby inertia forces are transmitted to the material as the trough moves in the forward direction, these forces causing the material to move forward during the reverse motion of the trough, a difference being made, depending on the amplitude of vibration, between simple shaking chutes and vibrating conveyers which are characterized by high vibration frequencies and small amplitudes, thus causing the material to perform a kind of micro-skipping motion.
It is known to equip such conveyer troughs with pre-loaded springs, the vibration being imparted to the conveyer by an eccentric drive at a frequency close to resonance of the natural frequency of the spring/mass system.
It is also known to mount the vibrating conveyers on a frame which is firmly attached to the foundation, the pre-loaded springs being located between the conveyer trough and the base frame, with the result that the induced forces have to be absorbed by the foundation, the disadvantage being that the foundation has to be absolutely rigid, especially in the case of long conveyers.
As a rule, a design of this type is unsuitable if such foundations are not available, e.g. when the vibrating conveyers have to be installed above the roof of a building, etc.
It is further known to provide a vibratory system comprising a conveyer trough and frame, the frame not being attached to the foundation directly but via supporting springs, and the frame acting as the countervibrating mass. When in use, this countervibrating mass vibrates in the opposite phase to the conveyer trough at an amplitude that is in an inverse ratio to the mass of the trough and which depends on the vibration amplitude of the trough. In this case, the vibrating conveyers also have to be of relatively heavy construction. Due to the necessary rigidity of the vibrating mass, there are also limits with regard to the overall length.